Automatic tractor trailer coupling

ABSTRACT

A system and method for automatically coupling at least one of an air line or an electrical line of a tractor to a trailer that is configured to be pulled by the tractor. A moveable arm is mounted to the tractor and is configured to exhibit at least one degree of freedom (DOF) of motion relative to the tractor. The moveable arm carries at least one of an air line connector or an electrical connector. A trailer coupling head is mounted to the trailer and carries at least one of an air line connector or an electrical connector that are configured to be connected to the at least one of an air line connector or an electrical connector of the tractor. The trailer coupling head can be moved in at least a vertical DOF relative to the ground by the automatic coupling system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of the following three ProvisionalApplications, the entire disclosures of which are incorporated herein byreference for all purposes: 62/873,550, filed on Jul. 12, 2019;62/898,327, filed on Sep. 10, 2019; and 62/946,472, filed on Dec. 11,2019.

BACKGROUND

This disclosure relates to coupling a tractor to a trailer.

Trailers are frequently docked or coupled, and undocked or uncoupled,from tractors in cargo yards, warehouse facilities, and intermodalfacilities. The docking and unlocking operations require humanintervention, making them relatively expensive and time consuming.

SUMMARY

The automatic tractor trailer coupling system and method involves atractor coupling head that is movably carried by the tractor, and atrailer coupling head that is carried by the trailer. The heads carrydevices that are used to couple air lines of the tractor to air lines ofthe trailer, such as lines for braking and emergency braking.Additionally or alternatively the heads carry devices that are used tocouple electrical lines of the tractor to the trailer, such aselectrical signals that are used for trailer running and braking lights.The degrees of freedom (DOF) of motion needed to bring the couplingheads into proper alignment and contact to accomplish the air/electricalcoupling are provided in part on the tractor side and in part on thetrailer side. At least the tractor side has active motion control. Byallowing motion in one or more DOF on the trailer side, the complexityof tractor side assembly can be reduced. In some examples the trailercoupling head can be moved in at least a vertical DOF relative to theground. In an example this trailer coupling head vertical DOF can beaccomplished by providing for passive motion of the trailer couplinghead in the vertical DOF. In another example this trailer coupling headvertical DOF can be accomplished by control of the height of the trailervia automated control of the tractor boom that controls the height ofthe tractor's fifth wheel coupling that is configured to couple with theking pin of the trailer.

In an example there are two DOF in the tractor side and two DOF ontrailer side. In an example the tractor DOF can include Z axis (fore andaft) translation and Y axis (vertical) rotation (i.e., yaw). In anexample the Y axis is locked until a threshold torque load is exceeded.The Y axis rotation is passive. The Z axis translation is driven by oneor more actuators. No vision system is needed. There are simple sensorsfor active control. In an example, in the trailer there are Y axistranslation and Y axis rotation DOF. The trailer side DOF motions arepassive. In another example the height of the trailer is controlled viacontrol of the tractor fifth wheel boom. This can reduce or eliminatethe range of Y axis translation needed on trailer side. The system canbe fully automated, or it can be operated by a human using a controller.

In an example the trailer side coupling head is in a fixed X axis(horizontal axis) location. Variation in trailer position relative tothe tractor creates a volume of possible locations in space for thetrailer coupler location relative to the tractor. The largest dimensionof this volume is along the Z axis, second largest dimension is alongthe Y axis, the third is along the X axis. This information can be usedto constrain the design of the auto-coupling system, to lower itscomplexity and cost.

The range of positions of a trailer relative to the tractor that ispulling the trailer also defines a volume of space between the tractorand trailer where auto-coupling system structures cannot be located(because they could be impacted by the trailer as it rotates relative tothe tractor). A tractor side auto-coupling assembly must be locatedoutside of this “keep out” volume, while still being able to reach theentire volume of possible locations in space of the trailer side couplerrelative to the tractor. Off the shelf six DOF robotic arms may not beable to reach all required locations if they are located so that theyfit outside the keep out volume when folded out of the way. In anexample a folding arm assembly is located (in its retracted state)against or close to the back of the tractor. The arm is configured toextend sufficiently to reach the front of the trailer where the trailerside coupling assembly is located.

A two DOF arm (accommodating actively controlled Z axis extension andpassive Y axis rotation) has fewer active components to package,reducing its footprint. In an example Z axis translation is accomplishedusing folding arm sections, thus maximizing reach for givenfootprint/volume of the retracted arm. The arm can use four-bar linksand a traveling motor. The motor can use a worm drive that is not backdrivable. The Y axis rotation DOF can be incorporated in the arm, or inthe tractor side coupling head or coupling head carrier. In anotherexample Z axis translation of the tractor coupling head can beaccomplished with a different design of a linear mover, such as arail-based system where the tractor coupling head or its carrier ismoved along a horizontal rail.

In an example the tractor side exhibits three DOF, which can include Zaxis translation, Y axis rotation, and Y axis translation. The Y axistranslation DOF can be accomplished with an active linear actuator orpassive springs/flexures (which can be used if the range of required Yaxis displacement is reduced). Y axis rotational DOF can be incorporatedin the arm that carries the tractor coupling head. In an example atorque threshold must be exceeded before rotation is allowed; this keepsthe tractor coupling head from flopping around when moving in free spaceprior to contact with trailer side coupler. Breakaway can beaccomplished with a passive mechanical system such as with a separatelinkage and spring-loaded ball, or concentric ring with detents.

In an example the tractor coupling head carrier has passive alignmentfeatures. The tractor coupling head carrier has a slot to capture avertical bar of the trailer coupling head. When there is misalignment inthe lateral (X) dimension, a torque is applied that breaks away thetractor side in Y axis rotation. This misalignment can occur whentrailer is at an angle relative to tractor. In an example the passivealignment features are Y axis and X axis V-shaped locating ramps thatguide passive alignment features on the trailer side coupling head. Yaxis and X axis locating ramps guide vertical and horizontal alignmentshafts on the trailer side coupling head. In an example the Y axis guideramps are asymmetrical. In an example the alignment is biased so thehorizontal alignment shaft of the trailer coupling head impacts thelarger of the Y axis ramps. The Y axis ramps funnel the horizontalalignment shaft on trailer coupling head into a slot on tractor couplinghead carrier that positively locates the horizontal alignment shaft. TheX axis ramps on the tractor coupling head carrier funnel a verticalalignment shaft on the trailer coupling head into a second slot ontractor coupling head carrier to positively locate the verticalalignment shaft. Misalignment in the X axis applies torque to thetrailer coupling head when its vertical alignment shaft contacts an Xaxis ramp of the tractor coupling head carrier. When a preset torquethreshold is exceeded, a carrier within the trailer coupling head canbreak away and allow Y axis rotation to occur. Y axis ramp may be singlesided rather than V shaped. A latching linkage that is part of thetractor coupling head carrier latches onto the horizontal alignmentshaft of the trailer coupling head to hold the air couplings togetherunder clamping pressure. When the tractor coupling head clamps onto thehorizontal alignment shaft, it is released from the tractor couplinghead carrier and stays in place when tractor coupling head carrierretracts. When the tractor coupling head carrier re-engages with thetractor coupling head that is clamped to the trailer coupling head, theclamp is released and the tractor coupling head is fixed to the tractorcoupling head carrier, so the tractor coupling head is withdrawn whenthe tractor arm retracts.

A trailer coupling assembly includes structures for mounting theassembly to a trailer. The trailer coupling assembly can include a framethat is configured to be removably fixed to the trailer, and a couplinghead carried by the frame. The coupling head can include X and Yalignment shafts. The trailer side coupling assembly may include an RFIDtag or other identifying information, which may be permanently orremovable attached to various portions of the trailer coupling assembly.The coupling head may be fixed to the frame or may be detachable fromthe frame for easier storage. In an example the frame removably couplesto the trailer using magnets. The magnets can be coupled to the frameusing structures that accommodate variation in the trailer surfacegeometry. The magnets can be compliantly coupled to the frame orpivotably coupled to the frame. The magnets may be configured to slideor otherwise move a distance along the frame. The magnets may beconcentrated towards the front of the frame where forces from couplingwith the tractor coupling head are concentrated. Magnets may fix theframe to bottom of the trailer and/or to the front of trailer and/or toone or more sides of the trailer. In an example the frame can be removedusing a cam or pry lever built into the frame to separate the frame fromthe trailer. In an example the frame has locating features that canposition the frame relative to a side of the trailer. The locatingfeatures can also reference the front of the trailer. In an example thecoupling assembly incorporates a mounting bracket that is permanentlyaffixed to a trailer. The mounting bracket is simplified so it is veryinexpensive. The mounting bracket can be screwed, bolted, welded, orotherwise permanently affixed to the trailer. The mounting bracketincorporates features that allow a coupling head to be coupled to thebracket. The carriage assembly can incorporate mating features designedto be snapped into and out of the bracket, or be otherwise coupled tothe bracket, without use of separate fasteners—the bracket and carriageassemblies are designed with complimentary and proprietary mountingfeatures and structures. The bracket may incorporate othernon-proprietary features to allow other structures to be coupled to thebracket. The other features may include holes, slots, tabs, and thelike, which can be standardized coupling features. The other featuresallow trailer side couplers from other manufacturers to be coupled to astandardized mounting bracket. The entire coupling assembly can bepermanently affixed to the trailer.

In an example the trailer coupling assembly includes a carriage assemblythat includes a coupling head mounted to a carriage. The carriageincorporates one DOF of movement—Y axis translation. Rollers ride withinan extrusion track. The carriage is sprung in a positive Y axisdirection by a constant force spring against an adjustable hard stopthat can be used to set a default position, which reduces tolerance indefault position. A constant force spring is desirable because theamount of Y displacement would cause forces applied from a linear springto be larger than desirable near the ends of travel. A constant forcespring can be designed to minimize forces in negative Y direction toreduce require motor torque on trailer side motor, and also reducejamming. In one example, Y axis translation of up to 10 inches isaccommodated. In one example, Y axis translation up to 10″ and Y axisrotation is accommodated. In one example, Y axis translation up to 3″and Y axis rotation is accommodated, typically for use in a system withfifth wheel height servo control. A smaller range of Y axis translationcan be accomplished using flexures or springs rather than a carriage orother structure that can translate vertically.

In an example the trailer coupling head is mounted to the carriage withone relative DOF—Y axis rotation. The trailer coupling head may have aflat plate with a pair of standard glad hand seals that mate with a flatsurface of the tractor coupling head, which also incorporates a pair ofglad hand seals. The plates are pressed together and held in place underpressure with a clamp link incorporated on the tractor coupling headcarrier that clamps to the horizontal alignment shaft of the trailercoupling head. The clamp could affix to other structures such as thevertical alignment shaft or other features on the trailer coupling head.The trailer coupling head is flexibly coupled to air and electricalconnectors on the trailer.

The trailer coupling head can also incorporate standard glad handcouplers that allow tractors without automated couplers to be coupled tothe trailer. In this example a pressure driven diverting valve appliespressure to the appropriate connection. Connection to standard gladhands actuates a valve that seals off the automated coupler plateconnections. Connection to the automated coupling plate connectionsactuates a valve that shuts off the standard glad hands.

All examples and features mentioned below can be combined in anytechnically possible way.

In one aspect, a system for automatically coupling at least one of anair line or an electrical line of a tractor to a trailer that isconfigured to be pulled by the tractor includes a moveable arm mountedto the tractor and configured to exhibit at least one degree of freedom(DOF) of motion relative to the tractor, wherein the moveable armcarries at least one of an air line connector or an electrical connectorand a trailer coupling head mounted to the trailer and that carries atleast one of an air line connector or an electrical connector that areconfigured to be connected to the at least one of an air line connectoror an electrical connector of the tractor. The trailer coupling head canbe moved in at least a vertical DOF relative to the ground by theautomatic coupling system.

Some examples include one of the above and/or below features, or anycombination thereof. In an example the moveable arm is configured toexhibit two DOF and the trailer coupling head is configured to exhibittwo DOF. In some examples the moveable arm is configured to exhibit atranslational DOF in a longitudinal direction and a rotational DOF abouta vertical axis that is orthogonal to the longitudinal direction. In anexample the vertical axis rotation is locked until a threshold torqueload is exceeded. In an example a controller is configured to controlthe moveable arm translational DOF, and wherein the moveable armvertical axis rotational DOF is passive. In an example the moveable armcomprises a tractor coupling head, wherein the rotational DOF of themoveable arm is accomplished by providing for passive motion of thetractor coupling head.

Some examples include one of the above and/or below features, or anycombination thereof. In an example the trailer coupling head isconfigured to exhibit a translational DOF in a vertical direction and arotational DOF about a vertical axis. In an example the trailer couplinghead DOF are passive. In an example the moveable arm is configured toexhibit a translational DOF in a longitudinal direction that isaccomplished at least in part using folding arm sections. In an examplethe folding arm sections comprise four-bar links. In an example atraveling motor is mounted between arm sections and is configured totranslate the arm in the longitudinal direction, wherein the motortranslates when the arm is translated in the longitudinal direction.

Some examples include one of the above and/or below features, or anycombination thereof. In an example the moveable arm comprises a tractorcoupling head that is removably mounted at a distal end of the arm andis configured to be removably coupled to the trailer coupling head. Inan example a first set of sensors is configured to detect when thetractor coupling head is mounted at the distal end of the arm, and asecond set of sensors is configured to detect when the tractor couplinghead is coupled to the trailer coupling head. In an example a trailercoupling assembly is configured to be removably mounted to the trailerand comprises the trailer coupling head. In an example the trailercoupling head comprises horizontal and vertical alignment rods forguiding a tractor coupling head mounted to an end of the moveable arminto alignment with the trailer coupling head.

Some examples include one of the above and/or below features, or anycombination thereof. In an example the trailer coupling head is carriedby a frame that is configured to be removably coupled to the trailerwith magnets. In an example a controller is configured to control theheight of a fifth wheel of the tractor, to provide the trailer couplinghead vertical DOF relative to the ground. In an example the moveable armis configured to exhibit a translational DOF in a longitudinaldirection, a rotational DOF about a vertical axis that is orthogonal tothe longitudinal direction, and a rotational DOF about a horizontal axisthat is orthogonal to the longitudinal direction and the vertical axis.In an example the moveable arm comprises a tractor coupling head that isremovably coupled to a tractor coupling head carrier. In an example thetrailer coupling head comprises alignment features that are configuredto engage with the tractor coupling head carrier, to align the tractorcoupling head with the trailer coupling head.

In another aspect a method for automatically coupling at least one of anair line or an electrical line of a tractor to a trailer that isconfigured to be pulled by the tractor includes mounting a trailercoupling head to the trailer, wherein the trailer coupling head carriesat least one of an air line connector or an electrical connector thatare configured to be connected to the at least one of an air lineconnector or an electrical connector of the tractor and using anautomatic coupling system to translate a moveable arm that is mounted tothe tractor toward the trailer, wherein the movable arm is configured toexhibit at least one degree of freedom (DOF) of motion relative to thetractor, wherein the moveable arm carries at least one of an air lineconnector or an electrical connector. The trailer coupling head can bemoved in at least a vertical DOF relative to the ground by the automaticcoupling system.

In another aspect a trailer coupling assembly for coupling at least oneof an air line or an electrical line of a tractor to a trailer that isconfigured to be pulled by the tractor includes a frame that isconfigured to be mounted to the trailer and a trailer coupling head thatis carried by the frame, wherein the trailer coupling head comprises atleast one of a connector for an air line or a connector for anelectrical line that are configured to be connected to at least one of aconnector for an air line or a connector for an electrical line of thetractor, and at least one alignment rail for facilitating passiverotational alignment about a first axis between the trailer couplinghead and a tractor coupling head.

Some examples include one of the above and/or below features, or anycombination thereof. In an example the alignment rail folds up forstorage. In an example the first axis is a vertical axis. In an examplethe alignment rail comprises a structure that references the front,bottom edge of the trailer. In an example the trailer coupling headcomprises an opening for receiving the tractor coupling head. In anexample the trailer coupling head comprises at least one air lineconnector and at least one electrical connector. In an example thetrailer coupling head comprises a pair of air line connectors and atleast one electrical connector. In an example the at least oneelectrical connector is located between the pair of air line connectors.

Some examples include one of the above and/or below features, or anycombination thereof. In an example the trailer coupling head comprisesalignment features, wherein when the tractor coupling head engages withthe trailer coupling head, the alignment features engage with thetractor coupling head to align the tractor coupling head with thetrailer coupling head. In an example an alignment structure coupled tothe tractor coupling head is constructed and arranged to engage with thealignment rail. In an example when the alignment structure engages withthe alignment rail, a torque is applied about the first axis to rotatethe tractor coupling head into alignment with the trailer coupling head.In an example the tractor coupling head is constructed and arranged tobe removably clamped in place to the trailer coupling head. In anexample a latch and a solenoid that is configured to move the latchallow the tractor coupling head to either remain with trailer couplinghead or retract from the trailer coupling head.

Some examples include one of the above and/or below features, or anycombination thereof. In an example the trailer coupling head isconfigured to move in at least one DOF relative to the frame. In anexample the at least one DOF is translation along the first axis. In anexample the at least one DOF is rotation about the first axis. In anexample the trailer coupling head comprises first and second alignmentrails, wherein the second alignment rail is positioned to be orthogonalto the first alignment rail. In an example the second alignment railfacilitates rotational alignment about a second axis, between thetrailer coupling head and a tractor coupling head. In an example thefirst axis is vertical, wherein the trailer coupling head is configuredto ride along a vertically oriented track that is coupled to the frame.In an example the assembly further comprises a spring, wherein thetrailer coupling head is coupled to the spring to bias the trailercoupling head in a neutral position. In an example the frame isremovably coupled to the trailer with magnets.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a tractor-trailer combination.

FIG. 2 is a schematic view of aspects of a system for automaticallycoupling air lines and electrical lines from a tractor to a trailer.

FIG. 3A illustrates the arm of the system of FIG. 2 , in the folded orstowed position, FIG. 3B shows the arm fully extended toward thetrailer, FIG. 3C includes the tractor and trailer, and FIG. 3Dillustrates a pivot for the arm.

FIG. 4A illustrates an example of a tractor coupling head and couplinghead carrier about to mate with a trailer coupling head, and FIG. 4Bshows the two coupling heads mated.

FIG. 5A is a side view of the tractor coupling head carrier and thetrailer coupling head, while FIG. 5B is a top view thereof.

FIG. 5C illustrates the tractor coupling head carrier coming intocontact with the trailer coupling head, and FIG. 5D shows the two fullyengaged.

FIG. 6 is a side schematic view of the tractor coupling head andcoupling head carrier engaged with the trailer coupling head andillustrating sensors used for active control of the system.

FIG. 7A illustrates a latching mechanism of the tractor coupling head inthe unlatched position, and FIG. 7B in the latched position.

FIG. 8A illustrates an exemplary trailer coupling assembly that includesa frame and a coupling head, FIG. 8B is a top view of the coupling head,and FIGS. 8C and 8D are partial rear and side views, respectively.

FIG. 9 illustrates another trailer coupling assembly.

FIG. 10 is a cross-sectional view of different manners of mountingmagnets to a frame that allow for movements of the magnets.

FIG. 11 is a cross-sectional view of an air coupler for the system thataccommodates both the present automatic coupling system and standardtractor-trailer air coupling.

FIG. 12 illustrates another option for moving the tractor coupling headtoward and away from the trailer coupling head.

FIG. 13 is a schematic diagram of a control system for the couplingsystem.

FIG. 14 illustrates steps involved in automatically coupling air linesand electrical lines from a tractor to a trailer.

FIG. 15 illustrates steps involved in automatically de-coupling airlines and electrical lines from a tractor to a trailer.

FIG. 16 illustrates operations involved in an automatic trailer couplingsystem and method.

FIG. 17 illustrates a trailer coupling assembly.

FIG. 18A illustrates a tractor coupling head and coupling head carrierabout to engage with the trailer coupling assembly of FIG. 17 , and FIG.18B shows the two aligned and ready to be engaged.

FIG. 19A is a more detailed view of the tractor coupling head close toengagement with the trailer coupling head and FIG. 19B shows themengaged.

FIG. 20 schematically illustrates a frame for a trailer couplingassembly.

DETAILED DESCRIPTION

In the present automatic tractor trailer coupling system and method, thetractor coupling head is movable toward and away from the tractor, andthe trailer coupling head is carried by the trailer. The degrees offreedom (DOF) of motion needed to bring the coupling heads into properalignment and contact to accomplish the air/electrical coupling areprovided in part on the tractor side and in part on the trailer side. Atleast the tractor side has active motion control. By allowing motion inone or more DOF on the trailer side, the complexity of the tractor sideassembly is reduced. In one example the trailer coupling head isconstructed and arranged such that it is able to move passively in avertical DOF relative to the ground. In another example the trailercoupling head vertical movement DOF is accomplished by control of theheight of the trailer via automated control of the tractor boom thatcontrols the height of the tractor's fifth wheel coupling; in this casethere may be a very small passive vertical DOF of the trailer couplinghead to accommodate for slight vertical misalignment after fifth wheelheight control.

FIG. 1 is side view of a tractor-trailer combination 10, illustratingtractor 12 coupled to and ready to pull trailer 14 along ground 16.Coupling is accomplished by coupling of the tractor's fifth wheelcoupling 20 to the trailer kingpin (not shown). This establishes atrailer rotational axis 24. The height of fifth wheel 20 can becontrolled by controlling the angle of hydraulic boom 22.

In the subject system and method the tractor coupling head is movedtoward and away from the trailer (along a longitudinal Z axis). FIG. 2is a schematic view of aspects of a system for automatically couplingair lines and electrical lines from a tractor to a trailer. Movable arm30 is carried at the back 13 of tractor 12, via arm support 40. Arm 30is illustrated in its fully stowed (retracted) position 32, a partiallyextended position 34, and a fully extended position 36. Arm 30 carriestractor coupling head 42 (shown schematically) that is configured toengage with and be coupled to trailer coupling head 62 (shownschematically). The trailer coupling assembly 60 includes trailercoupling head 62 that is carried by frame 64. Frame 64 is coupled totrailer 14 such that the position of the trailer coupling head is withina known volume relative to the tractor when the tractor and trailer arecoupled. In some examples frame 64 is carried at the bottom, side,and/or front 15 edge of trailer 14 and configured to place coupling head62 just at or in front of the front 15 and at or close to the bottom 26.As explained in more detail below, since not all trailers are the same,this known volume positioning can be accomplished at least in part byreferencing the trailer coupling head to the front edge and/or a side ofthe trailer using an appropriately-designed frame that carries the head.

In the examples illustrated in FIG. 2 and in FIGS. 3A-3D, the arm isconstructed and arranged to move the coupling head along a straight linetoward and away from the trailer. These motions can be accomplishedusing two sets of four-bar links that are connected and synchronized bya traveling motor and an appropriate gear set, both schematicallyillustrated as 50, FIG. 2 . In the example of FIGS. 3A-3D coupling 72 iscarried by or coupled to the tractor. Arm 70 is carried by coupling 72.First four-bar linkage 74 is connected between coupling 72 and centralsupport 76 that also carries the motor and gear set. Second four-barlinkage 78 is connected between support 76 and tractor coupling headcarrier 80. As the motor (not shown) causes the two four-bar links topivot to allow the arm to retract and extend, coupling head carrier 80,with opening 82 that is used to accept the trailer coupling head, ismoved along a straight line.

A challenge of designing a device that will make a connection between atractor and trailer is achieving the necessary range of motion toaccommodate the large uncertainty in the z direction location of thetrailer coupling head while still having a small enough retracteddimension to remain outside of the “keep out volume” while towing thetrailer. The selected mechanism has a large range of motion and also asmall retracted dimension. A worm drive is a good candidate transmissionto drive this mechanism since it can create very high gear ratios and isnot back-drivable. A back-drivable transmission could be affected bysudden jolts and gravity while a transmission that is not back-drivablemaintains its position unless otherwise commanded. The tractor couplinghead carrier is connected to this link and experiences pure translationin the z direction. If a worm drive is used, a relatively low powermotor could be used to drive this mechanism since speed of activation isnot critical. Utilizing this double four-bar linkage, the arm extendsout in a straight line path to the trailer coupling head. This greatlyminimizes the complexity of the system. Additionally, unlike otherlinear actuator systems, this one folds into a small package, with anextended to retracted aspect ratio of about 4:1.

In an example the arm has at least two DOF of motion—translation alongthe Z (longitudinal) axis and rotation about the Y (vertical) axis. Inanother example the arm also has a Y axis translation DOF. The arm DOFare a means to help position the tractor coupling head such that itproperly interfaces with the trailer coupling head. Accordingly, the armDOF can be accomplished anywhere in the tractor coupling assembly,including in the arm itself, where the arm is coupled to the tractor, inthe tractor coupling head carrier, in the tractor coupling head, and/orby adjusting the height of the trailer itself. In the exampleillustrated in FIG. 3D the arm Y axis rotational DOF is accomplishedwith a pivot assembly 84 where the arm end coupling 72 is coupled totractor 12 rear portion 13. Pivot assembly 84 may be configured to allowfor rotation of the arm about the Y axis only after a threshold torqueis reached. This locks the arm (and thus the tractor coupling head) fromrotation around the Y axis unless a certain torque threshold is reached,at which point the arm and its tractor coupling head will be able topassively rotate about the Y axis. This rotation helps the y-z plane ofthe tractor and trailer coupling heads to come into alignment. In anexample the breakaway torque is desirably less than the length of theextended arm times the force required to slide the magnets that couplethe frame to the trailer, which is dependent in part on the types andquantity of magnets and their positions. As a rough estimate thebreakaway torque is in the range of 20-40 Nm at the rotation point,which is generally sufficient to keep the arm from rotating due tooutside forces such as gravity, wind, and vibrations, but easilyovercome by the coupling of the trailer coupling head without moving theframe. The releasable locking pivot can be designed in any conventionalmechanical manner, such as using cam plates and a spring in the bearing.

FIG. 4A illustrates an example of a tractor coupling head and couplinghead carrier about to mate with a trailer coupling head, and FIG. 4Bshows the two coupling heads mated. In an example, in order to align thetractor and trailer auto-coupling heads the tractor coupling head isheld inside of a carrier which has “V” shaped ramp features on bothsides and on at least one of the top and bottom. The trailer couplinghead has alignment shafts protruding from the sides in the x (lateral)and y (vertical) directions. The tractor coupling head carrier will bedriven in the z direction. As the tractor coupling head carrier isadvanced toward the trailer coupling head in the negative z direction(toward the trailer), the ramps will come into contact with thealignment shafts of the tractor coupling head. The trailer coupling headis arranged to have one or two passive DOF of motion. One DOF istranslational along the Y axis. The second, if present, is rotationabout the Y axis. As the tractor coupling head carrier continues toadvance the trailer coupling head will be passively translated and/orrotated about the Y axis to align with the tractor coupling headcarrier.

Tractor coupling assembly 80 includes coupling head carrier 90 andcoupling head 110 that is configured to mate to trailer coupling head130. Vertical bar 118 of coupling head 110 is used to reference couplinghead 110 into slot 97. As depicted, in this non-limiting example tractorcoupling head carrier 90 has double-sided ramps on the left and rightand receiving slots where the ramps meet. Ramps 91 and 93 on the rightside are configured to engage with horizontal alignment shaft 137 oftrailer coupling head 130 and guide it into slot 92. Ramps 94 and 101 onthe left side are configured to engage with horizontal alignment shaft138 of trailer coupling head 130 and guide it into slot 95. The bottomramps 96 and 98 that lead to slot 97 are configured to engage withvertical alignment shaft 134 of trailer coupling head 130 and guide itinto slot 97. Trailer coupling head 130 includes body 132, locatingfeature set 133 comprising alignment shafts 134, 137, and 138, air andelectrical fittings 140 that convey air and electrical signals that arereceived from the tractor through body 132 and to the trailer, viaflexible hoses/lines (not shown), and air seals and an electricalcoupling (not shown) on the face of body 132 that faces the tractorcoupling head.

Both the tractor coupling head and the trailer coupling head have outerfaces that are configured to mate and be coupled together, in order tocouple one or two air lines and/or electrical lines from the tractor tothe trailer. FIG. 4A depicts face 112 of coupling head 110, on which arelocated air seals 113 and 114 and electrical fixture or coupling 115.Air line coupling can be accomplished with seals on the faces of thecoupling heads that meet and are compressed when the heads are clampedtogether, to provide an air-tight seal. In an example the seals are thesame types that are used in the standard, manually-coupled glad-handseals used in the trucking industry. Electrical coupling can beaccomplished with a plug on one face and a mating receptacle on theother face that make electrical contact when the heads are clampedtogether. In an example pivoting latching arms 116 and 117 of couplinghead 110 are used to clamp onto shafts 137 and 138, to hold the twoheads together with the air seals and electrical couplers mated. Asexplained below, when the heads are latched together head 110 isreleased from supports 99 and 100 of carrier 90, and carrier 90 iswithdrawn by the arm into the stowed position.

FIG. 5A is a side view of the tractor coupling head carrier and thetrailer coupling head, while FIG. 5B is a top view thereof. FIG. 5Cillustrates the tractor coupling head carrier coming into contact withthe trailer coupling head, and FIG. 5D shows the two fully engaged. Inthis example the allowed motions are indicated by arrows A, B, C, D, andE. In an example all motions except motion “A” (translation of thetractor coupling head carrier) are passive. The vertical height ofparked trailers and therefore their coupling heads varies, as itcorresponds to the extension of the landing gear ‘legs’ that the fronthalf of the trailer rests on. The landing gear or legs of the trailerare set by humans. In the case of a truck yard, entering trailers aretypically brought into the yard by over the road OTR trucks, which comein a variety of heights. This can range from about 0.5 m below thedefault height of a yard tractor's fifth wheel, to about 0.3 m above it.In the case of the former, when the yard tractor goes to connect to atrailer, it usually features ramps on the back that will pick up thetrailer and bring it to the height of the tractor's fifth wheel. In thecase of the latter, the operator must raise the fifth wheel via the boomto meet the height of the trailer. After either is accomplished, theyard tractor will continue backing into the trailer until the kingpin iscaptured by the fifth wheel. After that has occurred, the subjectauto-coupling operation will be performed. With the lower trailers, theheight of the trailer coupling head is already the same as the height ofthe tractor coupling head. With the higher trailers, the asymmetric rampof the tractor coupling head carrier will pull down the elevated trailercoupling head and center it, then connect to it. After the auto-couplingcycle has been completed, the truck operator will bring the fifth wheelto its maximum height, which will pull the legs of the taller trailersoff the ground, and raise the shorter trailers even higher. The tractoris then free to drive away with the trailer without dragging the trailerlegs on the ground.

When bringing the trailer coupling head down to the correct dockingheight, the vertical shaft used for X-axis locating is brought down withit. See FIG. 5C for shaft 137 contacting ramp 91 and the trailercoupling head 130 being brought down by the ramp, to the centeredposition defined by slot 92, FIG. 5D. If brought too far, the pin mayinterfere with semi-truck wheels or frame. Accordingly, it is best if itis offset by its length above the plane of the trailer underside. Itshould maintain this raised position until it comes into contact withthe asymmetric ramp system, at which point it can be brought down fordocking and un-docking. It is thus best to bias the trailer couplinghead to the top of its vertical range. This can be accomplished via aspring system. However, conventional springs apply an increasing forcethe more they are compressed or extended, which in turn applies astronger force to the magnets holding the frame to the trailer undersideand causing a ‘slingshot’ effect when the arm is retracted. To counterthis jolt of energy, constant force springs (such as those typicallyused in self-retracting tape measures) tuned to the gravitational massof the trailer docking head can be used. These apply a constant amountof force across the entire range of engagement between the asymmetricramp and docking head, ensuring a smooth and consistent motion betweenthe two.

In this example only one DOF (Z axis DOF of the tractor coupling head)is controlled. Control requires positional feedback. Positional feedbackmay be accomplished using sensors that detect when the arm is retracted,and when the tractor and trailer coupling heads are engaged. This is onemethod, where the sensors detect when the arm is at the ends of itsrequired travel and do not need to sense where it is when the arm is atan intermediate location. A more complex sensing system could senseposition over the entire range of travel. The angle of the four-barlinks could be sensed as a measure of displacement, or lidar could beused to sense absolute distance of the tractor carrier head from thetrailer coupling head, or the distance of the carrier head from the armattachment point to the tractor, or use other methods.

FIG. 6 is a side schematic view of an assembly 150 including the tractorcoupling head and coupling head carrier engaged with the trailercoupling head, and illustrating sensors used for active control of thesystem. Operations of the system and its use of sensors is described inmore detail below. In an example there are at least four sensors neededto operate the automatic-coupling system. Sensor 160 is a (normallyopen) Hall effect sensor carried by tractor coupling head carrier 90(e.g., by support 99) is used in conjunction with permanent magnet 162in tractor coupling head 110 to sense when the tractor coupling head isin close proximity to or latched to the tractor coupling head carrier.If the proximity sensor is activated and the tractor/trailer headcapture linkage (described below) is in the unlatched position, then thetractor coupling head must be captured inside of the tractor couplinghead carrier. Sensor 164 is also a (normally open) Hall effect sensorcarried by the tractor coupling head 110 and used in conjunction withpermanent magnet 166 carried by the trailer coupling head 130 to sensewhen the tractor and trailer coupling heads are in close proximity witheach other. If this proximity sensor is activated, it means that thesystem is ready to attempt latching the tractor to trailer couplingheads, or that the heads are already latched. Another sensor (not shown)would be a pressure transducer that senses the air pressure in thetractor air system. After the tractor has been coupled to the trailerthrough the coupling heads the system will be charged with air pressure.If the pressure in the system drops and remains below a certainthreshold, the control system will interpret that as a failed aircoupling and will not attempt to tow the trailer. Another sensor (notshown) would be a proximity sensor or limit switch that lets thecontrols system know that the arm is in the fully retracted position.This sensor will tell the control system when to stop retracting the armand that it is okay to begin towing the trailer. The system can also usesensors to detect the position of the latching system, as described inmore detail elsewhere herein.

FIG. 6 also illustrates proper alignment and mating of air seal 114 onthe tractor coupling head and air seal 142 on the trailer coupling head.In most cases there are two sets of mating air seals, one set used tofluidly connect a brake air line of the tractor to the brake air line ofthe trailer, and the other set used to fluidly connect an emergencybrake air line of the tractor to the emergency brake line of thetrailer. In an example the air seals are the same seals used in thecommon “glad hand” type manual couplings used in the trucking industryto connect tractor air lines to trailer air lines.

FIG. 7A illustrates a latching system of the tractor coupling head inthe position where it is unlatched from the trailer coupling head, andFIG. 7B in the latched position. The latching system is used to latchthe tractor and trailer coupling heads together, to accomplish andmaintain the air/electrical coupling. The latching system alsocouples/decoupled the tractor coupling head from its carrier. In ageneral sense, the latching system serves multiple purposes. One is toclamp the tractor coupling head to the trailer coupling head withsufficient force to compress the glad-hand seals and create an air seal.Another is to interface with the tractor coupling head carrier in theunlatched position to retain the tractor coupling head inside of thecarrier.

Hydraulic actuator/mover 180 moves shaft 184 with shaft end 186 in andout. Linkage arm 190 is coupled to end 186 and pivots on fixed pin 194and pivot point 199. Fixed pin 198 that is within slot 196 establishestravel end points. Arm 190 has saddle 192 and clamp point 191. Shaft 138of the trailer coupling head is received in saddle 192. As the linkageis moved and approaches the latched position, the mechanical advantageincreases at the clamp point location on latch. After the linkagereaches the latched position it goes through an “over center” positionat which point the actuator will not have to exert any force to keep thecoupling heads clamped to each other. See FIG. 7B. A hard stop pin 198and associated feature (slot 196) are located so that the latchingmechanism can only move a very small amount past this “over center”position so that the two coupling heads are clamped to each other. Theactuator is not needed to hold them together in this position. The clampforce will be maintained by the hard stop feature. The linkage will bestable in this position, clamping the glad-hand seals together and/orkeeping the electrical connectors coupled together. In order to un-latchthe coupling heads, the actuator retracts and supplies a force to bringthe linkage past the over center position and back to the un-latchedconfiguration. In an example the two latch arms are connected by a rodacross the back. This rod serves a double purpose, as when the latch isunlatched from the trailer coupling head the rod catches on a feature ofthe tractor coupling head carrier (such as feature 152, FIG. 6 ) andlatches to it.

FIG. 8A illustrates an exemplary trailer coupling assembly 239 thatincludes a generally annular frame 240 and a coupling head 130 carriedby the frame. FIG. 8B is a top view of the coupling head, and FIGS. 8Cand 8D are partial rear and side views, respectively. In an exampleframe 240 is magnetically coupled to trailer underside 26 using magnets241. Alternatively, particularly for attachment to a container onchassis trailer arrangement (where there is typically a large steel baron the front of the container), the frame can be configured tomagnetically attach to the top and/or front face of the bar. These frameattachments may include a flange on a side, to align the frame to boththe side of the trailer and the front face of the trailer, forconsistent positioning of the trailer coupling head. Installation can bedone without tools by aligning the frame to the trailer and letting themagnets attach to the trailer surfaces. Removal can be performed witheither a separate or integrated pry tool, or a demagnetizer, forexample.

The trailer coupling head (including the body with its seals andfittings, and the horizontal and vertical alignments shafts) is coupledto a carriage 214 that has roller set 212 comprising top rollers 213 andbottom rollers 215. These rollers can roll within hollow roller guide(tube) 216. This allows the coupling head to move up and down along theY axis, as indicated by arrow B. Also, the carriage can have some playrelative to the guide to allow the trailer coupling head to pivot aboutthe Y axis, as indicated by arrow D, to provide for this DOF of thetrailer coupling head. In an example the Y-axis pivoting can beaccomplished by including an opening in body 132 that lies along the Yaxis and with the top of shaft 134 located in this opening andconfigured such that body 132 can rotate about the Y axis relative toshaft 134.

In an example, in order to achieve a rotational DOF in the trailercoupling head about the Y axis, the trailer coupling head is mounted toa carriage with only its rotation about the Y axis left free relative tothe carriage. The carriage has rollers attached to it meant to rollinside of an aluminum extrusion which will act as a track for therollers. The carriage rolling inside of the extrusion allows for thetranslation in the y direction necessary for the tractor and trailercoupling heads to come into alignment. The carriage may be sprung in thepositive y direction by a constant force spring against an adjustablehard stop to set its default position. The constant force spring(s) canbe made part of the roller assembly. Setting the position of thecarriage against an adjustable hard stop will allow for its positionaltolerance zone to be reduced. If its default position were driven by thespring stiffnesses in the assembly then this would introduce error intoits resting location due to the uncertainties in the spring constantsand friction within the system. In order to eliminate this uncertaintythe carriage may be sprung towards the positive y extreme of its rangeof motion which would mean that the tractor coupling head carrier wouldonly ever push down on the trailer coupling head to bring it intoalignment. Use of a constant force spring is desired since the maximum ydeflection of the coupling head is large enough that a spring with alinear spring constant could introduce undesirable force levels into themechanism when attempting to deflect the trailer coupling head to itslower extreme in the y direction. The force needed to deflect thetrailer coupling head in the negative y direction should be minimizedsince it contributes to jamming of the coupling mechanism and increasesthe necessary motor torque for the delivery linkage.

FIG. 9 illustrates another trailer coupling assembly 239 a that differsfrom assembly 239 in that only a small amount of vertical compliance isprovided for by spring 243 that couples head 130 to front 242 of frame240. Pictured is a flat leaf spring 243 with no moving parts, but a morecomplex constant force solution can also be implemented for smoothermovement. The flexure can bend up or down to accommodate relativelysmall vertical misalignment but resists bending in other directions.

Attachment of the trailer coupling head to the trailer can be through atemporary mechanism for easy installation and removal. Permanent magnetscan be used to attach to steel elements on trailers. Two of the morecommon types are storage trailers and container on modular chassis. Thetrailer coupling head may be modular to a variety of attachment platesor frames.

Storage trailers and refrigerator trailers generally have non-magneticfront and side faces and magnetic bottom faces which allow for thelargest attachment force via many distributed magnets. Container onchassis trailers feature a large magnetic (e.g., steel) bar on the fronton which magnets can be attached to the top and front face of Both ofthese attachment mechanisms can feature a flange on the side foraligning it to the edge of the trailer as well as the front face forconsistent positioning. Installation can be done without tools byaligning the plates to the trailer and letting the magnets attach to thesurfaces. Removal can be performed with either a separate prying tool,demagnetizer, or lifting cam built into the plates. See, e.g., FIG. 20 .

Trailer surfaces are often uneven from grease buildup, distortion fromimpacts, and manufacturing imperfections. Magnetic force is strongestwith two parallel plates. As there are a number of independent magnetsthey can be configured to independently pivot/move to provide thegreatest magnetic force to a trailer. FIG. 10 is a cross-sectional viewof different manners of mounting magnets to a frame that allow formovements of the magnets. Four different non-limiting mechanisms tomount magnets 252 to frame 240 a such that the magnets can move areillustrated in FIG. 10 . One, 251, is via a threaded rubber shockisolator 253 which allows for twisting in two axes while still applyinga normal force. Another 254 is via a plastic ring 255 which allows forone axis of twisting while applying a normal force equal to the springconstant of the plastic ring. Another 256 is via a coil spring 257 thatprovides for bending in two axes while maintaining some rigidity in thenormal axis. Another 258 is via a spherical misalignment nut 259 thatcan be used in conjunction or independently of these other methods togive better z constraint. Other mechanism that allow for movements ofthe magnets are contemplated, and are included within the scope of thisdisclosure.

FIG. 11 is a cross-sectional view of an air coupler 270 for a systemthat accommodates both the present automatic coupling system andstandard tractor-trailer air coupling via mating manually-operatedglad-hand couplers. For automatic coupling to be used in yards that havetrucks with automatic coupling arms and without them, the trailer sideair attachments should be able to accommodate air pressure from a normalglad-hand coupler and the present automated coupler. Coupler 270 (shownin cross-section) includes standard input 272 and output 274 glad-handcouplers, and auto coupling input 271. Pressure-driven diverter valveelement 275 will allow for air flow from either input while maintainingair pressure in the system.

FIG. 12 illustrates another system 277 for moving the tractor couplinghead toward and away from the trailer coupling head. In one non-limitingexample, rather than an extendable arm the tractor coupling head 42 acan translate toward and away from the trailer coupling head 62 a alonga track 278. In one non-limiting example, a linear actuator 280 ismounted to the base 279 of the tractor. The coupling head carrier isattached to the linear actuator and so translates back and forth, wherethe carrier removably carries the tractor coupling head. The tractorcarrier and coupling head can be essentially the same as previouslydescribed, with a difference being that they are constructed andarranged to mount to the linear actuator rather than to the end of theextendable arm.

More generally, system 277 contemplates moving the tractor coupling headalong a path-defining element, such as a track. A linear actuator is oneexample. In one example a linear actuator has a carrier plate that ridesalong a ball screw. A rotary motor spins the ball screw and the carrierplate translates. This is one example of a linear actuator, there areother known approaches. One could envision, for example, a rack andpinion geared system where a pinion gear rotates in contact with astationary rack gear, and the pinion gear translates along the rack asit rotates.

FIG. 13 is a schematic diagram of a control system 282 for the subjectautomatic coupling system. Controller 283 is input with data from all ofthe sensors 284, and is configured to control the armextension/retraction motor 285, the tractor/trailer coupling headclamping 286, and air line/electrical line actuation 287 (for after theheads have been coupled). In systems where the fifth wheel height iscontrolled (explained in more detail elsewhere herein), the fifth wheellift system 288 is also controlled.

FIG. 14 illustrates steps involved 500 in automatically coupling airlines and electrical lines from a tractor to a trailer. First, thetrailer arrives at the yard and a person attaches the trailer couplingassembly to the trailer, steps 501 and 502. After the tractor docks withthe trailer by coupling the fifth wheel to the trailer kingpin (step503) the controller causes the arm to extend (or otherwise causes thetractor coupling head to translate in the −z direction). When thetrailer coupling head is detected to be proximate to the tractorcoupling head, step 505, the arm is stopped, step 506. Next thecontroller causes the toggles of the coupling head locking system tolatch the tractor coupling head to the trailer coupling head, step 507,until the latching is detected, step 508. In an example, step 507involves driving the latch mechanism to uncouple the tractor couplinghead from the tractor head carrier and latching the tractor couplinghead to the trailer coupling head. The air supply from the tractor isthen provided to the trailer to pressurize the brakes, step 509, and thepressurization is checked, step 510. The controller then causes the armto withdraw, leaving the heads coupled together on the trailer, step509. Motion proceeds until the arm retracted position is detected, steps511 and 512. The tractor can then be used to move the trailer, step 514.If the subject system is used with a driverless system, the subjectcoupling system can be enabled to signal the driverless system that thetractor can move.

FIG. 15 illustrates steps 520 involved in automatically de-coupling airlines and electrical lines from a tractor to a trailer. The controllercauses the arm to extend (or otherwise causes the tractor coupling headcarrier to translate in the −z direction), step 522. When the tractorcoupling head is detected by the sensor in the tractor coupling headcarrier, step 523, the arm is stopped, step 524. Next the controllercauses the toggles of the head locking system to operate, so that thetractor coupling head is released from the trailer coupling head and thetractor coupling head is latched to its carrier, step 525. The latchingoperation ends when the latching of the tractor coupling head to thetractor coupling head carrier is detected, step 526. The controller thencauses the arm to withdraw, removing the tractor coupling head from thetrailer coupling head, step 527. Motion proceeds until the arm retractedposition is detected, steps 528 and 529. The tractor is then decoupledfrom the trailer (e.g., withdrawing the fifth wheel connector from thekingpin), step 530. The tractor can then leave, step 531. Lastly, and ifdesired, the person removes the trailer coupling assembly from thetrailer, and the trailer can leave the yard, steps 532 and 533.

FIG. 16 illustrate operations 550 involved in an automatic trailercoupling system and method, where the tractor coupling head is beingcoupled to the trailer, or the tractor coupling head is being removedfrom the trailer. These operations involve the controller interactingwith the system's sensors, and the controlled elements of the system.When a cycle is started (which typically occurs when a person drivingthe tractor operates a “start” command, or for an autonomous vehiclewhen the yard management system commands the autonomous tractor to pickup a particular trailer), step 551, the state of the tractor couplinghead and its carrier sensors is checked to determine if the tractorcoupling head is in its carrier or if it is coupled to the trailercoupling head. If the tractor coupling head is in its carrier then theoperation will involve latching the tractor coupling head to the trailercoupling head. The arm is extended, step 553, until the trailer couplinghead magnet is detected, step 554. The latch is then operated and thelatching of the two heads together is detected, steps 555 and 556. Thebrakes are pressurized and checked, steps 557 and 558. If the checkfails, latching is performed again. If it passes, the arm is withdrawnto its retracted position, steps 559 and 560. The arm is stopped and asuccessful auto-coupling is signaled, step 561. If in the alternativethe tractor coupling head is on the trailer the operation will involveretrieving it from the trailer. The arm is extended, step 562, until thetractor coupling head magnet is detected, step 563. The tractor couplinghead's latch is then operated to de-latch from the trailer coupling headand latch to the tractor coupling head carrier, step 564. The latchingis detected, step 565, and the arm is withdrawn, step 566. When theretraction (stowed) position is detected, step 567, the arm is stoppedand a successful de-coupling is signaled, step 568.

FIG. 17 illustrates a different trailer coupling assembly 300. Assembly300 includes frame 310 that is constructed and arranged to be removablycoupled to a trailer. Trailer coupling head 330 is fixed to frame 310.Since coupling head 330 is fixed, it has no DOF of motion relative tothe trailer, which simplifies its design. Trailer coupling head 330includes two air line connectors 336 and 338 (e.g., glad hand seals) andan electrical connector 340 that lead to lines 337, 339, and 341,respectively, to supply the air and electrical signals to the trailer.

Frame 310 includes linear support member 312 that is configured to belocated below the bottom of a trailer and carries magnets 314 thatcouple the assembly to the bottom of the trailer. This places head 330as close as possible to the bottom of the trailer, which minimizes theload on the magnets which in turn minimizes the number of magnets andthe size of the frame underneath the trailer. Also, since the opening334 of trailer coupling head 330 faces laterally not forward, when thetwo heads are coupled the coupling forces are primary lateral. Opening334 is funnel shaped so that it helps to guide the tractor coupling headinto proper alignment as the two are mated, as is further explainedbelow. The tractor coupling head can have some compliance relative toits carrier so that it can be successfully guided into proper alignmentwith the tractor coupling head. The linear nature of the magnet arrayprovides a substantial force that resists twisting or sliding of theframe during the coupling action.

Assembly 300 also includes horizontal alignment rods or tracks 320 and321 that lie along the X axis. Rods 320 are sized and shaped tointerface with rollers on the tractor coupling head as explained below.In an example rods 320 and 321 are pivotable relative to support 312(pivot 322 for rod 320 identified in the drawing), so that in the stowedposition they can lie alongside support 312. This minimizes storagespace that needs to be used for the trailer coupling assembly.Additional magnets can be placed on the tops or inward-facing sides ofrods 320 and 321 if it is desirable to couple the frame to the trailerwith more force.

FIG. 18A illustrates a tractor coupling head carrier assembly 400 thatincludes tractor coupling head 360 and coupling head carrier 410.Assembly 400 is moved along the Z axis toward and away from the trailercoupling assembly 300, as indicated by arrow F. FIG. 18B shows the twoassemblies engaged but before the coupling heads are engaged together.Y-axis misalignment can be accommodated by controlling the height of thetrailer. The trailer height (and thus the height of the trailer couplinghead) can be controlled using system controller 283, FIG. 13 , which istied into the tractor's existing fifth wheel lift system 288. In anexample height control is accomplished by sensing and activelycontrolling the angle of tractor boom 22, FIG. 1 . Boom angle sensingcan be accomplished with an inclinometer mounted to boom 22. The angleof the top surface of the fifth wheel coupling is very nearly equal tothe slope of the ground that the trailer is resting on. A secondinclinometer mounted to the fifth wheel could be used to monitor theslope of the ground and account for it in the control system. This canreduce the amount of y-direction alignment error. If the height of thetrailer coupling head above the boom is known (e.g., by measurementafter the trailer coupling head assembly is installed on a trailer), thecontrol system can be designed to automatically control the boom angleand thus the y location of the trailer coupling head.

By measuring boom angle relative to the ground the trailer coupling headcan generally be located to within a few inches of accuracy, with thelead contributor to uncertainty being the length of the traileraffecting the pitch, and the hilly environment the trailer is on addinguncertainty to angles. To achieve higher accuracy, the angle of thefifth wheel itself (which sits flush to the bottom face of the trailer)can be measured. As the trailer is raised up by the boom, the trailerwill begin to tilt backwards. Shorter length trailers will tilt morethan longer trailers due to their wheelbases on the ground, but bymeasuring the angle that the trailer is tilted relative to the boom,that can be compensated for. This also compensates for uneven terrainsuch as hills and slopes, and instead of bringing the trailer to just aset boom angle, the control system will now bring it to a position thatsatisfies a predetermined relationship between the two measured anglerelative to each other. There can still be some uncertainty in thedistance from the front face of the trailer to its pivot point for thefifth wheel, but this is generally on the order of sub-inches so can becompensated for via compliance built into the tractor and/or trailercoupling head, and/or the arm.

Additionally or alternatively, the trailer's front edge height positioncan be measured. In an example a pair of laser rangefinders spacedslightly vertically, set around the coupling height, can be used. Byraising the trailer into them, eventually the lower of the tworangefinders will stop measuring the front face of the trailer and willgo off the edge and measure a distance below the trailer. By detectingthis large difference between the two rangefinders, the trailer couplinghead is now known to be between the two rangefinders and raising can bestopped, providing sub-inch accuracy.

By using the fifth wheel boom control which already exists in currenttractors, Y axis translation is accomplished without having to includeit in either of the components that are added to the system toaccomplish automated coupling. Since a trucking yard will need a largenumber of trailer coupling assemblies, including the Y axis DOF in thetrailer coupling assembly increases their size, causing storage issues,and also increases their cost. Including Y axis translation in the armwould increase its cost as well.

Tractor coupling head carrier 410 includes a frame with frame members412-415 and rollers 416 and 418 carried on member 414 and located,sized, and shaped such that they will engage with rods or rails 320 and321. For example, rails 320 and 321 can have a unique shape (e.g., the vshape shown) and the rollers can have a complementary shape (e.g., aprojecting V shape that fits into the rail). The two heads may not bealigned well enough for them to mate properly. For example, there may bea small height difference (Y axis alignment error) and/or a slightmisalignment about the X axis (which can be caused if the front of thetrailer is not vertical, which can occur when the trailer is raised bythe tractor's fifth wheel), and/or a misalignment (due to the trailerbeing at an angle behind the tractor rather than straight behind it)between the two heads. To account for these misalignments, tractorcoupling head carrier 410 can pivot about the Y axis (e.g., using abushing at pivot point 404), caused by the rollers contacting rails 320and 321. The rail shape and shape of mating rollers allow both a small Yaxis height compensation and a small rotation about X axis, which may beneeded if the trailer is on a slope relative to the tractor or isotherwise tilted relative to the tractor. In some examples, complianceof the tractor coupling head about the X axis is accomplished passivelyand mechanically. In an example a “pitch” degree of freedom can beintroduced in the mechanism that latches the two heads together thatwould allow the tractor coupling head to rotate within twocircumferential latch slots on the trailer-side assembly. Other examplesinclude an elastic or rubber member between the tractor coupling headand the clamping member, a flexure system to allow rotation of thetractor coupling head without translation, or a shaft and bushing alongthe X axis with a friction clutch attached to discourage free-rotationbut light enough that the friction force could be easily overcome.Additionally or alternatively, the trailer coupling head can be designedto include a small amount of vertical compliance, such as by using theflexure spring shown in FIG. 9 . The funnel shapes of the mating headsensures proper alignment of the mating air seals and the matingelectrical connectors as the heads are brought together. The frame iscarried by arm end 402 (arm not shown) and is pivotable about the Y axisrelative to the arm end about point 404, to provide a rotational DOFabout the Y axis. Since this Y axis rotational DOF is moved from thetrailer coupling head, the trailer coupling head is simplified ascompared to the prior example; in this example it is in a fixed positionon the trailer.

If the trailer is parked at an angle (along the Z axis) relative to thetractor and there is yaw between them, as the rollers interface withrails 320 and 321 one roller will contact its rail before the other one.As the tractor head continues to be moved in the negative z direction,the tractor coupling head carrier frame will pivot about point 404,until both rollers contact their rails. Since the tractor coupling headhas a Z axis translational DOF, and rotational DOF about the x and yaxes, and since Y axis translation is accomplished via control of thefifth wheel (and potentially a flexure in the trailer-side assembly),the two heads will be aligned and can be clamped together.

After the heads are aligned as shown in FIG. 18B, they are movedtogether by clamping members 382 (which moves along the frame and isable to hold trailer coupling head in place) and clamping member 380(which moves along the frame and is able to move and push tractorcoupling head 360 into fixed trailer coupling head 330).

FIG. 19A is a more detailed view of the tractor coupling head close toengagement with the trailer coupling head, and FIG. 19B shows themengaged. When the heads are engaged glad-hand seals 336 and 362 aresealingly engaged and glad-hand seals 338 and 364 are sealingly engaged.Also, electrical couplings 340 and 366 are functionally engaged.Clamping member 380 is controlled, to move coupling head 360 intocoupling head 330. When the heads are clamped together a latching systemlocks the heads together, so they remain engaged after clamping force isreleased. In an example the latching system includes latches 372 and 374that are each pivoting arms of the tractor coupling head, with aterminal hook or catch that is engaged in a mating receiving slot in thetrailer coupling head. The latches can be moved (pivoted) using solenoid387 that is functionally coupled to arm portions 382 and 384 to movethese portions, causing the arms to pivot about points 373 and 375. Theheads will remain latched until the solenoid is energized to move thearms in the other direction and release the latches.

FIG. 20 schematically illustrates an alternative frame 430 for a trailercoupling assembly, mounted to the bottom 26 of trailer 14. Frame 430illustrates one non-limiting manner of building into the frame amechanical means of allowing the frame to be removed from the trailer.In this example a pry bar assembly 436 is an integral part of frame 430and includes long lever 438 that runs up along the front face of trailer14, and integral short lever 440 that lies underneath the trailer andabove frame member 432 that carries magnets 434. The trailer couplinghead is not shown in this view. The front corner 441 where levers 438and 440 meet is pivotably coupled to the end of frame 432. When lever438 is pulled down and away from the trailer (in direction 439), itpivots about end 441 of lever 440, thus pushing the front end of member432 away from the bottom of the trailer and releasing the magnets fromthe trailer.

Elements of some figures are shown and described as discrete elements ina block diagram. These may be implemented as one or more of analogcircuitry or digital circuitry. Alternatively, or additionally, they maybe implemented with one or more microprocessors executing softwareinstructions. The software instructions can include digital signalprocessing instructions. Operations may be performed by analog circuitryor by a microprocessor executing software that performs the equivalentof the analog operation. Signal lines may be implemented as discreteanalog or digital signal lines, as a discrete digital signal line withappropriate signal processing that is able to process separate signals,and/or as elements of a wireless communication system.

When processes are represented or implied in any of the block diagrams,the steps may be performed by one element or a plurality of elements.The steps may be performed together or at different times. The elementsthat perform the activities may be physically the same or proximate oneanother, or may be physically separate. One element may perform theactions of more than one block.

Examples of the systems and methods described herein comprise computercomponents and computer-implemented steps that will be apparent to thoseskilled in the art. For example, it should be understood by one of skillin the art that the computer-implemented steps may be stored ascomputer-executable instructions on a computer-readable medium such as,for example, flash ROM, nonvolatile ROM, and RAM. Furthermore, it shouldbe understood by one of skill in the art that the computer-executableinstructions may be executed on a variety of processors such as, forexample, microprocessors, digital signal processors, gate arrays, etc.For ease of exposition, not every step or element of the systems andmethods described above is described herein as part of a computersystem, but those skilled in the art will recognize that each step orelement may have a corresponding computer system or software component.Such computer system and/or software components are therefore enabled bydescribing their corresponding steps or elements (that is, theirfunctionality), and are within the scope of the disclosure.

A number of implementations have been described. Nevertheless, it willbe understood that additional modifications may be made withoutdeparting from the scope of the inventive concepts described herein,and, accordingly, other examples are within the scope of the followingclaims.

What is claimed is:
 1. A system for automatically coupling at least oneof an air line or an electrical line of a tractor to a trailer that isconfigured to be pulled by the tractor, comprising: a moveable armmounted to the tractor and configured to exhibit at least one degree offreedom (DOF) of motion relative to the tractor, wherein the moveablearm carries at least one of an air line connector or an electricalconnector; and a trailer coupling head mounted to the trailer and thatcarries at least one of an air line connector or an electrical connectorthat are configured to be connected to the at least one of an air lineconnector or an electrical connector of the tractor; wherein the trailercoupling head can be moved in at least a vertical DOF relative to theground by the automatic coupling system, wherein the moveable arm isconfigured to exhibit a translational DOF in a longitudinal directionand a rotational DOF about a vertical axis that is orthogonal to thelongitudinal direction.
 2. The system of claim 1, wherein the moveablearm is configured to exhibit two DOF and the trailer coupling head isconfigured to exhibit two DOF.
 3. The system of claim 1, wherein thevertical axis rotation is locked until a threshold torque load isexceeded.
 4. The system of claim 1, further comprising a controller thatis configured to control the moveable arm translational DOF, and whereinthe moveable arm vertical axis rotational DOF is passive.
 5. The systemof claim 1, wherein the moveable arm comprises a tractor coupling head,wherein the rotational DOF of the moveable arm is accomplished byproviding for passive motion of the tractor coupling head.
 6. The systemof claim 1, further comprising a trailer coupling assembly that isconfigured to be removably mounted to the trailer and comprises thetrailer coupling head.
 7. The system of claim 6, wherein the trailercoupling head comprises horizontal and vertical alignment rods forguiding a tractor coupling head mounted to an end of the moveable arminto alignment with the trailer coupling head.
 8. The system of claim 1,wherein the trailer coupling head is carried by a frame that isconfigured to be removably coupled to the trailer with magnets.
 9. Thesystem of claim 1, further comprising a controller that is configured tocontrol the height of a fifth wheel of the tractor, to provide thetrailer coupling head vertical DOF relative to the ground.
 10. A systemfor automatically coupling at least one of an air line or an electricalline of a tractor to a trailer that is configured to be pulled by thetractor, comprising: a moveable arm mounted to the tractor andconfigured to exhibit at least one degree of freedom (DOF) of motionrelative to the tractor, wherein the moveable arm carries at least oneof an air line connector or an electrical connector; and a trailercoupling head mounted to the trailer and that carries at least one of anair line connector or an electrical connector that are configured to beconnected to the at least one of an air line connector or an electricalconnector of the tractor; wherein the trailer coupling head can be movedin at least a vertical DOF relative to the ground by the automaticcoupling system, wherein the trailer coupling head is configured toexhibit a translational DOF in a vertical direction and a rotational DOFabout a vertical axis.
 11. The system of claim 10, wherein the trailercoupling head DOF are passive.
 12. A system for automatically couplingat least one of an air line or an electrical line of a tractor to atrailer that is configured to be pulled by the tractor, comprising: amoveable arm mounted to the tractor and configured to exhibit at leastone degree of freedom (DOF) of motion relative to the tractor, whereinthe moveable arm carries at least one of an air line connector or anelectrical connector; and a trailer coupling head mounted to the trailerand that carries at least one of an air line connector or an electricalconnector that are configured to be connected to the at least one of anair line connector or an electrical connector of the tractor; whereinthe trailer coupling head can be moved in at least a vertical DOFrelative to the ground by the automatic coupling system, wherein themoveable arm is configured to exhibit a translational DOF in alongitudinal direction that is accomplished at least in part usingfolding arm sections.
 13. The system of claim 12, wherein the foldingarm sections comprise four-bar links.
 14. The system of claim 12,further comprising a traveling motor mounted between arm sections andthat is configured to translate the arm in the longitudinal direction,wherein the motor translates when the arm is translated in thelongitudinal direction.
 15. A system for automatically coupling at leastone of an air line or an electrical line of a tractor to a trailer thatis configured to be pulled by the tractor, comprising: a moveable armmounted to the tractor and configured to exhibit at least one degree offreedom (DOF) of motion relative to the tractor, wherein the moveablearm carries at least one of an air line connector or an electricalconnector; and a trailer coupling head mounted to the trailer and thatcarries at least one of an air line connector or an electrical connectorthat are configured to be connected to the at least one of an air lineconnector or an electrical connector of the tractor; wherein the trailercoupling head can be moved in at least a vertical DOF relative to theground by the automatic coupling system, wherein the moveable armcomprises a tractor coupling head that is removably mounted at a distalend of the arm and is configured to be removably coupled to the trailercoupling head, the moveable arm further comprising a first set ofsensors that is configured to detect when the tractor coupling head ismounted at the distal end of the arm, and a second set of sensors thatis configured to detect when the tractor coupling head is coupled to thetrailer coupling head.
 16. A system for automatically coupling at leastone of an air line or an electrical line of a tractor to a trailer thatis configured to be pulled by the tractor, comprising: a moveable armmounted to the tractor and configured to exhibit at least one degree offreedom (DOF) of motion relative to the tractor, wherein the moveablearm carries at least one of an air line connector or an electricalconnector; and a trailer coupling head mounted to the trailer and thatcarries at least one of an air line connector or an electrical connectorthat are configured to be connected to the at least one of an air lineconnector or an electrical connector of the tractor; wherein the trailercoupling head can be moved in at least a vertical DOF relative to theground by the automatic coupling system, wherein the moveable arm isconfigured to exhibit a translational DOF in a longitudinal direction, arotational DOF about a vertical axis that is orthogonal to thelongitudinal direction, and a rotational DOF about a horizontal axisthat is orthogonal to the longitudinal direction and the vertical axis.17. The system of claim 16, wherein the moveable arm comprises a tractorcoupling head that is removably coupled to a tractor coupling headcarrier.
 18. The system of claim 17, wherein the trailer coupling headcomprises alignment features that are configured to engage with thetractor coupling head carrier, to align the tractor coupling head withthe trailer coupling head.
 19. A method for automatically coupling atleast one of an air line or an electrical line of a tractor to a trailerthat is configured to be pulled by the tractor, comprising: mounting atrailer coupling head to the trailer, wherein the trailer coupling headcarries at least one of an air line connector or an electrical connectorthat are configured to be connected to the at least one of an air lineconnector or an electrical connector of the tractor; and using anautomatic coupling system to translate a moveable arm that is mounted tothe tractor toward the trailer, wherein the movable arm is configured toexhibit at least one degree of freedom (DOF) of motion relative to thetractor, wherein the moveable arm carries at least one of an air lineconnector or an electrical connector; wherein the trailer coupling headcan be moved in at least a vertical DOF relative to the ground by theautomatic coupling system, wherein the moveable arm is configured toexhibit a translational DOF in a longitudinal direction and a rotationalDOF about a vertical axis that is orthogonal to the longitudinaldirection.